Permutations.php
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<?php
namespace PhpOffice\PhpSpreadsheet\Calculation\Statistical;
use PhpOffice\PhpSpreadsheet\Calculation\Exception;
use PhpOffice\PhpSpreadsheet\Calculation\Functions;
use PhpOffice\PhpSpreadsheet\Calculation\MathTrig;
use PhpOffice\PhpSpreadsheet\Shared\IntOrFloat;
class Permutations
{
/**
* PERMUT.
*
* Returns the number of permutations for a given number of objects that can be
* selected from number objects. A permutation is any set or subset of objects or
* events where internal order is significant. Permutations are different from
* combinations, for which the internal order is not significant. Use this function
* for lottery-style probability calculations.
*
* @param mixed $numObjs Integer number of different objects
* @param mixed $numInSet Integer number of objects in each permutation
*
* @return float|int|string Number of permutations, or a string containing an error
*/
public static function PERMUT($numObjs, $numInSet)
{
$numObjs = Functions::flattenSingleValue($numObjs);
$numInSet = Functions::flattenSingleValue($numInSet);
try {
$numObjs = StatisticalValidations::validateInt($numObjs);
$numInSet = StatisticalValidations::validateInt($numInSet);
} catch (Exception $e) {
return $e->getMessage();
}
if ($numObjs < $numInSet) {
return Functions::NAN();
}
$result = round(MathTrig\Factorial::fact($numObjs) / MathTrig\Factorial::fact($numObjs - $numInSet));
return IntOrFloat::evaluate($result);
}
/**
* PERMUTATIONA.
*
* Returns the number of permutations for a given number of objects (with repetitions)
* that can be selected from the total objects.
*
* @param mixed $numObjs Integer number of different objects
* @param mixed $numInSet Integer number of objects in each permutation
*
* @return float|int|string Number of permutations, or a string containing an error
*/
public static function PERMUTATIONA($numObjs, $numInSet)
{
$numObjs = Functions::flattenSingleValue($numObjs);
$numInSet = Functions::flattenSingleValue($numInSet);
try {
$numObjs = StatisticalValidations::validateInt($numObjs);
$numInSet = StatisticalValidations::validateInt($numInSet);
} catch (Exception $e) {
return $e->getMessage();
}
if ($numObjs < 0 || $numInSet < 0) {
return Functions::NAN();
}
$result = $numObjs ** $numInSet;
return IntOrFloat::evaluate($result);
}
}